I have a 4.5 year old Rheem 50 gallon gas hot water heater that has started to leak. Sometimes the leak is a steady trickle. It originates from under the heater. Each time the leak occurs it will run for sometime. The leak will then quit and the basement floor will dry up as though there was never a problem. This occurs on a daily basis. The hot water volume has not appeared to decline, however, I have noticed I have to turn the shower valve further towards hot. The leak is not from the overflow nor from the drain valve. Neither is there condensation. The heater is under warranty. Doesn't the sign of a leak from within always indicate a water heater replacement -- either right now or very shortly in the future?